:::caution

<Icon name="exclamation-triangle" /> **Re-Enabling document.domain Injection**

As of Cypress [v14.0.0](/app/references/changelog#14-0-0), [`document.domain`](https://developer.mozilla.org/en-US/docs/Web/API/Document/domain)
will no longer be injected into `text/html` pages by default.

This means you must now use `cy.origin()` when navigating between different _origins_
in the same test. Previously, `cy.origin()` was only necessary when navigating between
different [superdomains](/app/guides/cross-origin-testing#Parts-of-a-URL) in the same test.

By setting the
[injectDocumentDomain](/app/references/configuration#injectDocumentDomain) configuration option to `true`,
Cypress will attempt to inject `document.domain` into `text/html` pages.

A superdomain is comprised of the trailing two elements of the hostname, delimited by
a `.` (period). Given `https://www.cypress.io`, the superdomain is determined to be
`cypress.io`. When this option is enabled, `cy.origin()` is not necessary when navigating
between `https://www.cypress.io` and `https://docs.cypress.io`, but is necessary
when navigating between `https://www.cypress.io` and `https://www.auth0.com`.

- This will cause issues with certain sites, especially those that use
  [origin-keyed agent cluster](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Origin-Agent-Cluster)s.
- This option is deprecated, and will be removed in a future version of Cypress.
  :::
